Muffler



K. G. CARTER Nov. 22, 1960 MUFFLER Filed Dec. 23, 1957 INVENTOR /7Z'7V I f/Z7 6. 634572 BY I ATTORNEY United States Patent MUFFLER Kenneth G. Carter, 1815 Glen Drive, Jackson, Mich.

Filed Dec. 23, 1957, Ser. No. 704,450

2 Claims. (Cl. 181-35) The invention relates to silencers and particularly pertains to carburetor intake silencers for internal combustion engines.

The noise produced by the air rushing into the carburetor of internal combustion engines becomes objectionable under certain circumstances such as on an outboard motor during trolling and it is an object of the invention to provide an efficient silencer or mufller for this purpose.

Yet another object of the invention is to provide a carburetor intake silencer which may be economically produced from stampings, and is concise in size.

Another object of the invention is to provide an intake silencer which will effectively suppress vibrations produced by air rushing into the carburetor, yet does not produce undesirable resistance to the air flow or objectionable air flow characteristics.

These and other objects of the invention will become apparent when viewed with regard to the following description and accompanying drawings wherein:

Fig. l is an elevational view of the silencer of the invention as attached to a carburetor,

Fig. 2 is an exploded perspective view of the components of the silencer,

Fig. 3 is a longitudinal cross section view of the assembled silencer,

Figs. 4, 5 and 6 are cross section elevational views taken along the lines IV-1V, V-V, and VIVI of Fig. 1, respectively.

Basically, the silencer of the invention consists of three sheet metal stampings which are riveted together. The silencer may be made from any desired material such as steel, brass, aluminum, etc., or may be made of sheet plastics or other non-metallic substance. The upper portion of the silencer consists of a shell 10 which is of a semi-teardrop configuration formed with a flange 12 about the entire periphery or parting line. The configuration of shell 10 is such that if flange 12 is placed on a planar surface an enclosure is formed having a maximum height and width at one end and reducing to the minimum height and Width at the other end. Rivet holes 14 are formed in flange 12 and two extra large holes 16 are formed in the flange adjacent the smaller end for affixing the silencer to the carburetor.

An inner cover 18 is used to enclose the underside of shell 10 in the assembled state and consists of a substantially planar stamping in which rivet holes 20 and carburetor stud holes 22 have been formed. A circular opening 24 is also formed in cover 18 near the smaller end through which passes the air flowing to the carburetor. Another opening 26 is formed in cover 18, however, opening 26 is substantially transverse to the general plane of the cover 18 and is formed by slitting cover 18 and raising portion 28 above the general plane of the cover.

An outer or intake cover 30 is adapted to be affixed to the underside of cover 18 to complete the silencer of the invention. As best shown in Fig. 2, cover 30 is approximately half of the size of the cover 18 and is formed with a straight edge 32. The cover 30 is depressed at 34 whereby an arcuate opening 36 is formed when the cover is held in contact with the inner cover 18. Outer cover 30 is also formed with rivet holes 38 for assembly purposes.

Assemblying the silencer is merely a matter of aligning rivet holes 14, 20 and 38 and inserting and swaging rivets 39 therein to affix the shell 10, inner cover 18 and outer cover 30 together as shown in Fig. 3. When assembled in this manner the opening 24 will open into the smaller volume end enclosed by shell 10, and the portion 23 and portion 34 will form a duct 40 of substantially parallel sides and uniform cross sectional area throughout its length, open to the atmosphere at one end and to the chamber defined by shell 10 and cover 18 at the other end.

The silencer may be attached to a carburetor 42 as ilustrated in Fig. 4, e.g., the studs 44 mounted on the carburetor housing project through the aligned holes 16 and 22 of shell 10 and cover 18, respectively, and nuts 46 will maintain the opening 24 in line with the air in take of the carburetor 42. Thus assembled and aflixed in position, the silencer will channel air drawn into the carburetor first up through the duct 40 into the shell 10, the air stream will then reverse direction of travel and will converge toward the opening 24 due to the configuration of shell 10. The air thus directed into the carburetor will be sufficiently agitated to achieve eflicient mixing with the fuel without producing objectionable resistance to the air flow. The void defined by shell 10 and cover 18 will act as an effective noise suppressing chamber and duct 40, which substantially projects back toward the carburetor forming a baffle, will also reduce the noise level produced by the carburetor breathing.

It will therefore be appreciated that the invention provides an economical, eflicient and concise intake silencer which may be quickly assembled to the carburetor and which will easily fit within a motor housing and other space restrictive locations.

Although only one embodiment of the invention has been described and illustrated it will be understood that various modifications may be apparent to those skilled in the art without departing from the spirit and scope of the invention.

I claim:

1. A sound vibration silencer comprising a shell having a planar flange formed thereon, a substantially planar inner cover attached to said flange enclosing said shell and defining a chamber between said shell and inner cover, the configuration of said shell being such that said chamber decreases in volume from a first end to the second end, a first opening in said inner cover communicating with the reduced volume end of said chamber,

a second opening in said inner cover communicating with the larger volume end of said chamber, the plane of said second opening being substantially at right angles to the plane of said inner cover, an outer cover afiixed to said inner cover and extending therealong so as to permit flow through said first opening, said outer cover being formed with a recessed portion forming a duct communicating with said second opening and the atmosphere.

2. A silencer comprising a bulbous shell having a planar flange formed thereon, a substantially planar inner cover engaging said flange and defining a noise suppression chamber within said shell, an opening in one end of said inner cover communicating with said chamber and adapted to be placed over the noise vibration source, a raised portion formed on said inner cover extending toward said shell, a second opening in said cover at one end of said raised portion, an outer cover adjacent to said inner cover and extending therealong so as to permit flow through said first opening, a depressed portion on said outer cover in opposite relation to said raised portion, the configuration of said raised and depressed portions being such that a parallel sided duct is formed between said inner and outer covers open to said chamber and the surrounding atmosphere and fastening means projecting through said flange, inner cover and outer cover maintaining said shall and covers in assembled relationship.

References Cited in the file of this patent UNITED STATES PATENTS Murphy Jan. 22, 1924 Smith June 28, 1927 Haas June 15, 1937 Kiekhaefer July 9, 1957 Hesse et a1. June 10, 1958 FOREIGN PATENTS Great Britain May 15, 1930 

